| Which of the following is categorised as a parasite in true sense? |
| a) | Koel (cuckoo) | b) | Housefly |
| c) | Human foetus | d) | Head louse |
| (d)Parasitism It is a relationship between two living organism of different species in which one organism called parasite obtains food directly from another living organism called host. In given options only louse fulfil all the parameters of parasitism |